Grinding machine



June 22 1926.

F. E. GARDNER GRINDING MACHINE Filed June 3, 1921 2 Sheets-Sheet 1 ATYY' \NVENTQR a'cf @ara na' June 22 1926. 1,589,593

F. E. GARDNER GRINDING MACHINE Filed June 5, 1921 2 Sheets-Sheet 2 R O m W VJ 1| 1| I I n m mm r 6 t .5 F. m 00 j g n w MT 7 I a, N I x m m MW N WT I "I' I ||L Om II Mm H x MN P, MN 2: N mm\ w @p C N I Patented June 22, 1926.

UNITED STATES FREDERIC E. GARDNER, OF IBELOI'I, WISCONSIN.

GRINDING Application filed June 3,

This invention relates to grinding machines of the type known in the trade as disk grinders in which pieces or objects to be ground are passed between the opposed grinding faces of annular grinding disks. The invention covers modifications and improvements in the construction, arrangement and operation over that of the machine in my copending application Serial No. 72,977 filed May 27, 1921.

In the arrangement of this invention, two annular grinding disks are mounted opposite each other with their supporting spindles in axial alinement, and an important object of the invention is to provide improved arrangement for supporting shields in the adjacent ends of the annular grinding disk apertdres for preventing Work parts from falling into the apertures from the carrier and also to guide such parts into and out of the grinding fields. A further object is to so support the shields that they will automatically maintain their roper positions with reference to the grin ing faces when adjustment is made to compensate for wear on the grinding elements.

The above and other features of my invention are incorporated in the machine shown on the accompanying drawing, in which drawing Fig. 1 is an end elevational view,

Fig. 2 is a sectional view on plane 22 of Fig. 1,

Fig. 3 is a sectional view of the grinding structure, housings and carrier, on plane 3-3, Fig. 1,-and

Fig. 4 is an end view showing the manner of supporting the shield suspending rods.

In the structure shown the machine base 10 supports at its opposite ends sub-base structures 11 and 12 on which are repectively mounted the carriers 13 and 14 for the annular grinding disks 15 and 16. The carriages l3 and 14 are of similar construction and each is mounted on guideways 17 to be longitudinally shiftable or adjustable on the respective sub-base. Each has also journal boxes 18 for journaling the grinding wheel spindle 19 which between the journal boxes carries the belt pulley 20 by means of which the spindle is rotated. At the inner end of each spindle is secured a head 21 in which is seated the respective grinding disk 15 or 16 as clearly shown in Fig. 2. The spindles are in axial alinement so that the grinding PATENT OFFICE.

MACEIN E.

1921. Serial No. 474,586.

disks are concentric with their grinding liminary adjustment and fon then giving them a final accurate adjustment. A screw shaft 21 is rotatable in the bracket 22 but is confined against longitudinal movement by the collars 23. The threaded end of the shaft extends through the walls 24 and 25 on the carriage and between these walls the shaft receives the threaded hub 26 on which is the worm wheel 27 which. is engaged b the worm 28 on the countershaft 29 whicli is suitably journaled in walls of the carriage and which at its outer end has the hand wheel 29. The outer end of the screw shaft is squared to receive a wheel or crank and when this shaft is thus turned the carriage is comparatively rapidly shifted, the threaded hub being locked by the engagement of the worm wheel with the worm. For final adjustment the shaft 21 is held against rotation and the wheel 30 is turned, slow movement being then imparted to the carriage by virtue of the worm and worm wheel gearing. Adjustments can thus be rapidly and accurately made for the proper gap between the grinding faces.

The work carrier shown is in the form of a plate 30 extending transversely of the machine in a vertical plane between the grinding elements. At its ends the plate is secured on the uprights 31 and 32 extending from the ends of the base 33 which is slid ably mounted on the track structure 3; secured on the intermediate wall 3 1' of the base 10. Strips 35 secured to the underside of the base engage below the track flanges 36 to keep the base in proper alinement on the rail during reciprocation of the carrier. Near one end of the plate 30 of the holder is the opening or pocket 37 for receiving objects to be ground. lVith the arrange ment shown the object is carried with the holder through the grinding field between the opposed annular grinding elements and is then carried back to permit removal of the object and insertion of another object. Feeding and discharging of the objects from the carrier may be manually or automatically performed.

Provision must be made to separate the grinding elements sufliciently to permit pas- .on ways 38.

base a bracket 39 journals a shaft 40 on which is the belt pulley 41. At its outer end the shaft carries a worm 42 which meshes ...with the worm wheel 43 secured on one end of the shaft 44, this shaft being journaled in the bearing extension 45 on bracket 39 and in the bracket 46 on the machine base. At the other end of the shaft 44 is secured the cam 47 which engages with the cam roller 48 at the lower end of the lever 49. Intermediate its ends the lever is pivoted on pin 50 supported in the bracket 51, and at its upper end the pin 52 pivots the lever to the outer'end of the sub-base 11. Between the lower end oftthe lever and the machine base is interposed a compression spring 53 which tends to swing the lever to cause the subi-base to shift inwardly. The spring has the adjustable abutment 54 on the lever b means of which its compression force can e adjusted. The inward movement of the sub-base is limited b the stops 55 which are secured on the sun-base and abut against the end of the machine base 10.

The contour of the cam 47 is such that its engagement with the cam} roller will swing the lever to shift the sub-base 11 outwardly against the force of the spring 53, and will then permit the spring to return the lever to gradually shift the carriage inwardly so that the grinding faces are gradually brought together after receiving an object whereby the object is gradually ground to the degree desired, grinding stopping as soon as the stops 55 engage with the machine base. The grinding element 15 is thus positively shifted away from the element 16 but yieldingly though forcibly returned by the power exerted by spring 53. The pin 50 on which the lever 49 is pivoted is preferably eccentric so that further adjustment may be made to obtain accurate movement of the sub-base 1T.

The mechanism for reciprocating the work carrier is operated in timed relation with the retraction of the sub-base 11 to separate the rinding elements for the reception of work.

n the shaft 44 which supports the worm wheel 43 is also mounted a bevel pinion 56 which meshes with the bevel gear on the countershaft 57 on which countershaft is the gear pinion 58 which meshes with the idler gear 59 which engages the gear 59' on the horizontal shaft 60. The shaft 60 is 'ournaled in bearings 61 and at its inner end as the crank arm 62 from which extends the crank pin 63 into the slot 640f a gear sector 65 trunnioned at its lower end in the bearing 66. The sector gear meshes with a rack 67 secured to the underside of the work holder base 33, the track 34 having the passageway (38 through which the sector extends.

The shaft 60 rotates in clockwise direction (Fig. 1) and by virtue of the pin and slot connection shown a very desirable variable speed of travel is imparted to the work carrier. 1n the position of the parts shown in Fig. 1 the pocket 37 of the work carrier is outside of the grinding elements ready to receive a piece of work to be ground. As the shaft 60 is now rotated, the crank pin 63 increases its distance from the axis of the gear sector and the carrier travels slowly to carry the work into position between the overlapping grinding faces, and such slow movement continues while the work is being carried along between the faces so that ample time is given for thorough and efficient grinding. When the crank arm is in vertical position the movement is the slowest and the work will be in the middle of the grinding field. When the crank arm passes the vertical position the crank pin starts to travel downwardly in the slot and the speed of the work holder accelerates and such acceleration rapidly increases as the pin approaches the lower end of the slot, the result being that the ground piece of work is rapidly carried back through and out of the grinding field, and as it leaves the field the sector radius again increases and the carrier movement is slowed up until it reaches its outermost position. At the end of its outer stroke the carrier is practically at a standstill for a short period of time and ample opportunity is provided for inserting and adjusting a piece of work in the holding pocket. Just before a piece of work reaches the grinding field to be ground the grinding elements are separated to receive the work, such' separation being automatically accurately performed at the proper time by the mechanism already described.

The extent of swing of the gear sector 65 is such that the work carrier will be moved a distance to carry the pocket 37 with the work therein across the radial width of the grinding elements at that side of the machine. If desired, a second work holder pocket 68 may be provided in the plate 30 for carrying work between the grinding elements at the opposite side of the machine. it being thus possible to greatly increase the capacity of the machine. \Vhere only one pocket is used, only one retraction of the grinder carriage is necessary fpr each back and forth travel of the work carrier. However, if both sides of the machine are used, then there should be two retractions of the grinder carriage for each back and forth travel of the carrier. This can be readily taken care of by the proper gearing relation be ween the'shaft 60 and the cam shaft 44.

With the two hole arrangement there will be a retraction of the grinding element 15 to receive work placed in the pocket 37 and while the work is traveling between the grinding surfaces at that side of the machine, the grinding elements are pressed together to effect grinding. After the work in pocket 37 has been carried into the grinding elements the pocket 68 will be outside of the grinding elements to receive a piece of work and when the carrier is moved in the opposite direction to carry this work toward the grinding element, the element 15 is again retracted so that the work in pocket 68 is received between the grinding faces on the left side of the machine. \Vhile the work is being ground and carried to the inside of the grinding elements, the finished work in pocket 37 is carried out. Owing to the crank pin and slot connection the gear sector will shift the work carrier 30 more rapidly toward the left than toward the right (Fig. 1) so that grinding at the right side of the machine will be more rapid than that at the left. However, for certain classes of work such rapid grinding is very desirable.

To assist in guiding objects into and out of the grinding fields, I provide'guide plates 69 and 70 which are in line with the work receiving pockets and which may be supported from the hoods or housings 71 and 72 mounted on the sub-base structures 11 and 12 respectively. To prevent objects from falling off the carrier into the apertures of the annular grinding disks and also to guide the objects when they are carried out of the grinding elements. I provide the shields 7 3 and 74 in the respective apertures adjacent the grinding faces. The shield 73 is supported at the inner end of the rod 7 5 which extends axially through the spindle 19 and is held against longitudinal movement by collars 76 on the rod at opposite sides of the arm 77 through which the rod extends, the arm extending upwardly from the sub-base 11. The rod 78 which supports the shield 74 extends through the arm 79 on the sub-base structure 12 and is held against longitudinal movement by the collars 80. The rods are free to rotate as at times the objects are partly between the grinding faces and partly between the shields. As the grinding disks are worn down by grinding operation and dressing operation, the carriages 13 and 14 are adjusted to compensate for such wear and the grinding faces are thus kept, in proper alinement with reference to 'the shields. The shields cooperate with the guide plates to guide the objects accurately with reference to the grinding fields as they are carried back and forth with the carrier.

Although the subdiase structure 12 is not adjustable longitudinally on the machine basegit may be tilted on its horizontal axis 81 by means of jack screws 82, and the carriage 14 is adjustable on its vertical axis 83 by means of set screws 84. By means of this adjustment the grinding face of the disk 16 may be kept in true parallelism with the grinding face of the element 15.

I claim as my invention:

1. In a grinding machine of the class described, the combination of a base, a carriage adjustable on said base, a spindle journaled on said carriage, supported on one end of said spindle, a rod extending through Said spindle, an arm ex tending from said base for supporting said rod, and a shield on said rod and engaging in the grinding disk aperture.

2 In a grinding machine of the class described, the combination of a base, a carriage adjustable on said base, a spindle journaled on said carriage, an annular grinding disk mounted on said spindle, a rod extending axially through said spindle, a shield at the inner end of said rod supported thereby within the grinding disk aperture, and means for preventing longitudinal movement of said rod relative to saidbase.

3. In a grinding machine of the class described, the combination of a base, a carriage adjustable on said base, a spindle journaled on said carriage, an annular grinding disk on said spindle, a work carrier movable in front of said disk to carry work into contact with the disk, a rod extending axially through the spindle, a shield on the inner end of said rod for closing the grinding disk aperture, said rod being rotatable with said disk but being locked against longitudinal movement therewith.

4. In a grinding machine of the class described, the combination of an annular grinding disk, a work carrier movable in front of said disk to support work to be ground, a supporting spindle for said disk, a rod extending axially through and being rotatable with said spindle, a shield on the inner end of said rod closing said disk aperture, and means for effecting relative adjustment between the grinding disk and shield.

5. In a grinding machine of the class described, the combination of an annular grinding disk having an aperture, a work carrier movable in front of said disk and aperture, a. shield closing said aperture at its outer end, and a supporting stem for said shield extending axially with reference to said grinding disk.

6. In a grinding machine of the class described, the combination of a base, a carriage movable on said base, a spindle journaled on said carriage, an. annular grinding disk mounted on said spindle, means for adjusting said disk a'xially,-a shield positioned within the disk aperture and substantially closingthe same. and means extending into said disk supporting said shield, said last an annular grinding diskmentioned means being unaffected by adjustment of said disk.

7 .In a grinding machine of the class described, the combination of a base, a carriage 5 movable on said base, a spindle journaled on said carriage, an annular grinding disk mounted on said spindle, a rod extending I into the disk aperture, and a shield at the inner end of said rodsupported thereby in the grinding disk aperture.

In testimony whereof, I have hereunto set my hand.

FREDERIC E. GARDNER. 

